Wednesday, August 31, 2016

Hurricane Hermine sweeps into Florida's Big Bend

Hurricane Hermine made landfall at 1:30am Friday morning near St. Marks, Florida. Damage is widespread in the Big Bend area of The Sunshine State. (NBC News)
A strengthening Hurricane Hermine roared into the Big Bend area of north Florida overnight, making landfall near St. Marks at 1:30am. The storm, which has been extremely difficult to predict, has now been downgraded to a tropical storm, 50 miles northeast of Tallahassee. Hermine leaves behind major damage and flooding along Florida's Gulf Coast from Tampa to Tallahassee. Early estimates place the storm surge at 9 feet as Hermine moved inland. Overnight winds gusted in excess of 80 mph along the coast, with isolated tornadoes. Numerous trees and power lines are down, with nearly 200,000 residents without power. Many roads have been closed as a result of flooding. Authorities had to rescue people early Friday morning who had attempted to ride out the storm along the coast. Remarkably, Hermine was the first hurricane to hit Florida since Wilma in 2005.

A spectacular image of a strengthening Hurricane Hermine (upper right) just prior to landfall in Florida early Friday morning. (NOAA)
Hermine is the little storm that could; Expected to become a tropical storm, a week ago, the system defied forecasters and remained as a depression well into the Gulf of Mexico, before turning abruptly north and rapidly intensifying on Thursday. Hermine is expected to remain a strong tropical storm with heavy rain and winds up to 70mph across the southeast and into the Middle Atlantic states this weekend. Weather warnings stretch from southern New Jersey to Florida. The storm may impact eastern Canadian weather next week, but it is too soon to determine exactly how far north she will go. Hermine is forecast to stall off the east coast near New Jersey next week.

Goodbye to meteorological summer

National Hurricane Center forecast map for soon-to-be tropical storm Hermine. The storm is forecast to impact Florida over the next 48 hours before heading up the east coast. (National Hurricane Center)

Today is the last day of the summer season as far as meteorologists are concerned. Thankfully, Mother Nature lingers a little behind, so we can still expect more summer weather here in Montreal, usually well into September. But the signs of autumn are there: the kids are back to school, leaves turning slightly, and longer, cooler nights producing heavy morning dew.

Looking back briefly at June through August, temperatures averaged above-normal values. Some locations in southern Quebec and New England are expected to show their warmest August on record. Until the middle of August, it was also a very dry summer in Montreal. That has changed in the last two weeks, with more rain falling this month than in the previous two combined. Overnight, Montreal added to the monthly total as scattered thunderstorms developed. More are possible later Wednesday, before we say goodbye to August. At this time, the long holiday weekend looks spectacular here in southern Quebec, sunny and seasonable, with high temperatures in the middle 20s.

Across North America, the weather has been extremely active of late. A powerful and rare summer low pressure area pounded Newfoundland Monday and Tuesday, with torrential rain and winds in excess of 130km/h. A wind gust to 121km/h in Twillingate was the strongest August wind on record for that community. The previous record was 107km/h, set in 2007. Strong thunderstorms this week have produced severe flash flooding in Ohio and parts of Colorado. Deep hail fell in Colorado Springs on Monday, requiring snow plows to clear the streets.

Satellite image of tropical depression 9, Wednesday morning over the Gulf of Mexico. This system is forecast to strengthen into tropical storm Hermine later today. (NOAA)
The Tropics
In the tropics, tropical depression 9 is still meandering in the Gulf of Mexico, 640km south of the Florida coast. This system is expected to strengthen into a tropical storm later Wednesday, and be named Hermine. Warnings are in effect for a portion of the big bend area of Florida, as well and the Atlantic coast northward into Georgia. Heavy rain, up to 300mm (12 inches), and 60mph winds are forecast over the next 24 to 36 hours. The storm is then expected to move back over Atlantic waters over Labor Day weekend. All interests up and down the east coast of the US into Atlantic Canada will need to pay close attention to the future path of this tropical storm. Further out in the open waters of the Atlantic, hurricane Gaston has become a major storm, with 115mph winds. Gaston is no threat to land at this time. Meanwhile in the Pacific Ocean, hurricanes Madeline and Lester are expected to pass dangerously close to Hawaii over the next 48 hours. Warnings are in place for Madeline, forecast to move just south of the Big Island early Thursday morning.

Sunday, August 28, 2016

The 5th Anniversary of Hurricane Irene


Torrential rain consumed many villages in central and southern Vermont, including Quechee shown above. (NWS)
August 28th is the 5th anniversary of the multi-billion dollar Hurricane Irene arriving in Quebec. Irene had humble beginnings as a weak area of low pressure off the west coast of Africa. The storm was the 9th tropical system of 2011, becoming the first hurricane of the season. Irene would sweep across the Bahamas as a major Category 3 hurricane before weakening and heading for the east coast. Irene made the first of two landfalls on August 27, 2011 at Cape Lookout, North Carolina, as a high end Category 1 storm.

By the time Irene would rain herself out over Atlantic Canada, nearly eight million east coast homes would be without power, and insurable losses would approach US$10 billion. Irene would cause extensive damage to coastal North Carolina, with a storm surge washing over portions of the Outer Banks. The storm then moved inland southwest of New York City and tracked across Vermont and into the Eastern Townships of southern Quebec. Along her path torrential rain would fall, with as much as 250mm (9 inches) in less than 24 hours. The resulting flash flooding would heavily damage numerous villages and towns across the Catskills of New York and into the Green Mountains of Vermont. The flooding in Vermont would be the worst natural disaster in that state since the flood of 1927. In the end, 49 fatalities were attributed to the storm, including one in Quebec. The raging Yamaska River east of Montreal washed out a section of road, contributing to the drowning of a motorist.

A satellite image from August 28, 2011 shows Hurricane Irene engulfing New England and southern Quebec. (NOAA)
In Quebec, Irene produced as much as 150mm (6 inches) of rain in the Charlevoix region and sections of the Beauce and Townships. In Montreal, 65mm (2.5 inches) of rain fell in less than five hours. Winds gusted over 100km/h in Quebec, including a peak gust of 113km/h on Ile d'Orleans. In Montreal, the highest gust was 90km/h. The wind and rain contributed to power outages, with nearly 250,000 Quebec homes in the dark. The power at my home on l'Ile Perrot was out for over 20 hours. Final damage estimates in Quebec exceeded $130 million.

Irene was one of the first storms that tapped into the wave of social media. The storm threatened a large population along the east coast of the US, and was therefore heavily publicized. New York City was shut down for an entire weekend. In the end, many felt the storm was over-hyped. Unfortunately, this drew attention away from Vermont and upstate New York, where Irene was one of the worst natural disasters on record. Irene proved just how devastating a low-category hurricane can be, especially to inland locations.

Thursday, August 25, 2016

The tropics are heating up

NOAA, National Hurricane Center image of Hurricane Gaston, and Invest 99-L (orange X) in the Atlantic basin. At this time, Invest 99-L has a better-than-even chance of becoming tropical storm Hermine. The storm could then impact south Florida as early as this weekend.
We are entering the most active period in the Atlantic hurricane season, which typically runs from June 1st to November 30th. Most of the storms occur within a six-week period from late August to early October, focused around Labor Day.

Forecasters at the National Hurricane Center in Miami, Florida are currently watching two systems in the Atlantic basin. Hurricane Gaston is a minimal storm with 75mph winds, located over 1000 miles east of the Leeward Islands, and not any threat to land. Gaston is expected to weaken over the next 24 hours as it moves into cooler waters. Of more interest this morning to forecasters and weather nerds alike, is an area of showers and thunderstorms dubbed Invest 99-L, just north of Puerto Rico. Depending on your weather model of choice, this low pressure area could become tropical storm Hermine this weekend and impact south Florida. Beyond that, different models are presenting very different scenarios. If the system develops, and that is still not certain, it could swing northeast out to sea, or impact the waterlogged central Gulf Coast as a strong storm next week.

In any event, I will be monitoring this storm closely, as I have been doing since 1979 when my interest in hurricanes started. Many of these storms impact eastern Canada with heavy rains and strong winds. Case in point: Hurricane Irene, whose 5th anniversary is coming up later this week. Irene generated over $1.5 million dollars in damage and one fatality in Quebec back in 2011. It was also the costliest natural disaster in Vermont state history. I will have much more on Irene later this week.

Monday, August 22, 2016

Autumn-like start to the week

Another spectacular warm and humid morning sky on L'Ile Perrot this past Friday, August 19. Summer will take a brief break today before returning Tuesday.
A wet and windy cold front on Sunday afternoon ushered in a brief taste of fall for southern Quebec. This morning temperatures are as cool as they have been at any time this month. It was 14C (56F) at 7am on L'Ile Perrot. The front also added to our quickly-recovering summer rainfall totals, with another 15 to 25mm falling on Sunday, 21.6mm here on L'Ile Perrot. That actually lifts us to close to normal precipitation since June 1st, with over 125mm (5 inches) falling in just the last week.

Today will be partly cloudy and fall-like, with a high temperature near 20C (68F) and very comfortable humidity levels. Clear skies tonight will allow for cool lows between 10C and 14C (50 to 55F) in southern Quebec. On Tuesday, warm southwest winds will return, along with high temperatures rising rapidly to 27C (81F). The balance of the week will see a return to warm and humid weather, with highs approaching 30C (86F) once again. The warm weather will last through Friday, before another cold front arrives with showers and thunderstorms. At this time next weekend looks sunny, warm and dry.

Wednesday, August 17, 2016

Record rainfall for Montreal

Torrential rain slowed the evening commute in Montreal. A record-setting 67mm fell on the city in less than five hours Tuesday night. (ValleyWX Photo)

Tropical rains fell across southern Quebec and Ontario late on Tuesday, with a record 67mm at Trudeau Airport in Dorval, most of that falling between 2pm and 9pm. That amount shattered the previous 24-hour record for August 16 of 49.5mm, established in 1966. It also rapidly brought the August total for the city from nothing to 119mm in just four days. The average August rainfall for Montreal is 94.1mm. Heavy rain and strong winds created widespread power outages across the region. As of early Wednesday morning, nearly 100,000 Hydro Quebec customers were in the dark. That number has since fallen to around 35,000 as of noon, August 17. Hydro Quebec has not specifically mentioned the cause, but a substation in Mercier-Hochelaga-Maisonneuve was flooded and knocked offline last evening.

The rain and poor visibility may have also contributed to accidents in which two pedestrians were struck by cars, in different parts of the city. Some underpasses were also flooded, but for the most part the water drained well. The ground has been parched lately and water levels have been very low, so the runoff was quick.

Other amounts of rain reported last evening included 58mm at my home on L'Ile Perrot, 77.8mm downtown at the McTavish recording station, 75mm at Oka, 90mm in Wiarton, Ontario, 58mm in Kemptville, Ontario and 26mm in Ottawa. South of the border in Vermont, heavy localized rain from thunderstorms washed out a section of Route 100 in Duxbury.

Warm and humid weather will now be with us through the weekend, with highs from 28 to 30C (83 to 86F) and warm lows near 20C (68F). The humidex readings will climb from the low to middle 30s by the weekend. Scattered thunderstorm activity is possible over the weekend, in the soupy air mass.

Tuesday, August 16, 2016

Heavy rain warning for Montreal

Heavy rain warnings have been posted for Ontario and Quebec. 
(AccuWeather.com map)

Widespread heavy rainfall warnings have been issued by Environment Canada for southern and eastern Ontario and southern Quebec. The same system that has created the devastating flooding in Louisiana will lift northeast across the Great Lakes and towards Quebec. The good news is that the system will be moving fairly quickly through our region. Rain will spread west to east across Ontario this morning and into Montreal later this afternoon. The rain will be heavy at times tonight, along with thunderstorms.

The death toll has risen to nine in Louisiana after nearly 25 inches of rain. Widespread historic flooding is occurring. The photo above is from Prairieville, Louisiana. (Photo via Twitter @presleygroupmk)

At this time, we can expect 40 to 60mm of rain across the region, with as much as 70mm locally. The heavy rain comes on the heels of the 50 to 100mm that fell over the weekend, however we are not expecting any major flooding. Southern Quebec and Ontario were bone dry for the past six weeks and water levels are very low. We should be able to absorb the new precipitation without incident. There may be some minor ponding of water in low-lying areas and on roadways. Temperatures will be rather warm and muggy, with a high of 25C (77F) today and 27C (81F) Wednesday. Overnight lows will be near 20C (68F). Skies will slowly clear in Montreal on Wednesday.

Monday, August 15, 2016

Heavy rain from Louisiana to Quebec and Ontario

Historic flooding across Louisiana has resulted in at least four fatalities and thousands of evacuations and water rescues. (Photo via Twitter @cbcnews)
What a difference a few hours can make when it comes to the weather. In less than 48 hours, many portions of southern Quebec and eastern Ontario recorded more rain than in the previous six weeks. Heavy tropical rains, along with embedded thunderstorms, swept along the edge of a large Bermuda high to our southeast. Southern Quebec reported 50 to 100mm (2 to 4 inches) of rain over the weekend, the heaviest along the Ottawa Valley, through Montreal and into the Townships. Here on L'Ile Perrot, I measured 78mm from late Friday to early Sunday. That included nearly 27mm in just a couple of hours, during a thunderstorm early Sunday morning. The normal monthly rainfall in August is 94.1mm for Montreal. Some severe weather was also observed, with tree damage in the eastern Townships, as well as minor flooding being reported. In Ontario, at least two tornadoes were confirmed on Saturday, including an EF-1 (150 to 175km/h winds) along the shores of Lake Simcoe.

LOUISIANA FLOODING
The soupy weather across eastern North America is the result of a large Bermuda high sitting off the east coast of the US. This system is pumping extremely warm and humid air north and west. Searing heat has been gripping the large east-coast cities of the US, as well as southern Ontario. We had a break on Saturday, as clouds and rain managed to keep the temperatures down here in Montreal. Along the edge of the high is a conveyor belt of moisture running from the Gulf of Mexico into Quebec. Therefore the closer to the Gulf, the more rainfall. Unprecedented historic flooding is occurring in Louisiana, with a least four fatalities reported. Thousands of water rescues have occurred, in addition to tens of thousands more evacuated. The flooding was the result of nearly 2 feet of rain in less than 48 hours. Damage is widespread across the state, including the closure of Interstate 10.

After the severe drought conditions of the last month, more rain is expected in southern Quebec late Tuesday and Wednesday, with perhaps another 25 to 50mm. Temperatures will warm up again for Monday, reaching 28C (83F) this afternoon in Montreal.

Thursday, August 11, 2016

Much needed rain this weekend

Tropical moisture may help alleviate some of the drought conditions in Ontario and Quebec this weekend. (AccuWeather.com Map)
7AM Friday Morning Update: A few weak thunderstorms this morning deposited a few millimetres of rain on L'Ile Perrot and Montreal. This was the first precipitation in 18 days. More rain is expected this weekend, possibly heavy at times. A flood watch is in effect for northern New York and Vermont. The same conditions prompting that watch state side, will exist in southern Quebec, with 25 to 75mm (1 to 3 inches) of rain possible through Sunday. Temperatures will be warm all weekend, in the middle 20s, and it will be very muggy.

Previous post below:
It remains hot and humid across eastern Canada this week, but with no rain here in southern Quebec. The last rainfall in Montreal was way back on July 25th. Hot weather has returned this week, with daytime high temperatures well into the 30s on Wednesday. Montreal fell just shy of the 1944 record of 32.8C (91F), with a high of 32.5C (91F) recorded at Trudeau Airport. Ottawa reached 35C (95F), and Toronto a scorching 36C (97F).

Thursday will feature the exact same weather, but more oppressive, as humidity levels rise. Overnight temperatures in Montreal remained uncomfortable, in the low-to-middle 20s, with highs today expected to reach the low-to-middle 30s. Combined with the humidity, the humidex or real feel temperatures will reach 40C (104F). Starting Friday, deep tropical moisture will lift north from the Gulf of Mexico. As it interacts with a front over eastern Canada, heavy rainfall is possible. The rain will come in waves, along with very muggy temperatures. Expect showers and thunderstorms from Friday through Sunday. It will not rain all the time, but when it does, it could be rather heavy at times, with some local flooding. The possibility exists for 25mm to as much as 75mm of rainfall in some locations across eastern Ontario, southern Quebec and New England. The rain will be beneficial to the moisture-starved vegetation. Temperatures will remain warm, but not as warm as we have experienced, due to thick cloud cover. Highs in Montreal will range in the middle 20s, with lows in the upper teens.

Monday, August 08, 2016

Drought conditions worsen in Quebec and Ontario

Southwest Quebec is experiencing moderate-to-severe drought conditions. It has not rained in two weeks. (plantmaps.com)

You cannot understate how dry the weather has been across southern Quebec and Ontario. According to the most recent data, most of southern Quebec is either abnormally dry or in a moderate drought. The far southwest, including L'Ile Perrot, Hudson, Valleyfield, northwest towards the Ottawa Valley, is currently showing as being under a severe drought. As you travel further southwest into Ontario, conditions are even worse, ranging from severe to extreme drought, including Toronto.

Similar conditions are occurring across southwest and eastern Ontario as well. This map is from early July. The situation has since become extreme in portions of the GTA. (Agriculture Canada)

We need rain! The last measurable rainfall at Trudeau Airport in Montreal was 5.8mm on July 25. Cumulative rainfall for the summer season so far is running at 40 to 50 percent of normal for Montreal. Ottawa has recorded even less rainfall. Couple that with the prolonged stretches of hot weather, and you have the recipe for drought. On Friday, Montreal recorded one of the warmest days of the summer at 34C (93C). This established a new record high for the date, surpassing 32.9C (91F) from 1988. More heat is forecast this week, with the mercury expected to reach the upper 20s today and low-to-middle 30s the balance of the week. Forecasters are watching the weekend for perhaps the most significant amount of rain so far this summer for Montreal. A moisture-laden storm system may move close enough to the St. Lawrence Valley, by Friday. That event is several days away, so we will have to wait and see how the system plays out.

In the meantime, conserve water. The signs of heat stress are widespread. Most of the lawns on L'Ile Perrot look like hay, the plants are wilting and numerous trees are starting to shed their leaves. Additionally, water levels on area lakes and streams are very low. Use caution when boating.

Friday, August 05, 2016

Slightly cooler, less humid weekend for Montreal

With temperatures into the low 30s, by the lake in Pointe Claire was one of the few spots you could cool off naturally this past week. (ValleyWeather)
Thursday was another hot day in Montreal, as the temperature nudged above 32C (90F) once again. We can expect the same today, along with elevated humidity levels. The forecast high should range from 31 to 33C (88 to 92F). A strong cold front will arrive across eastern and southern Ontario this afternoon, advancing into southern Quebec tonight. Along the front, strong thunderstorms are forecast to develop in Ontario this afternoon. As the front moves into our region, we can expect a round of showers and storms as well, but I think their strength may diminish here in Quebec. The reason for this is that the front should arrive in Montreal after the warmest part of the day, allowing for more stability in the atmosphere. We will have to watch this scenario, as warnings may be needed for a portion of the region.

Behind the front, cooler air will arrive, along with lowering humidity levels. Saturday will be unsettled to start the day, with some showers around Montreal, but partial sunshine by afternoon. Temperatures will be much cooler this weekend, around 25C (77F). Fair weather is expected to start next week with perhaps showers by Wednesday. Temperatures will warm again into the upper 20s.

Active severe weather continues to be widespread across North America this summer. Since Sunday, nearly a dozen tornadoes have been reported across the northern plains into southern Saskatchewan and Manitoba. At least five have occurred on the Canadian side of the border. Winds in excess of 100km/h, heavy rain and large hail were reported in Manitoba on Wednesday.

The tropics are beginning to awaken as well. Hurricane Earl moved into Belize on Thursday, with heavy rain and 120km/h winds. Earl is close to the Bay of Campeche this morning, and is forecast to weaken further as the system slides into mainland Mexico. Heavy rain, up to 300mm, is possible along the path of the storm. National Hurricane Center forecasters are watching other areas of the Caribbean Sea and Atlantic for further development next week.

Tuesday, August 02, 2016

July 2016 into the history books

This tornado south of Yorkton, Saskatchewan, destroyed one home on Sunday afternoon. (Twitter Photo @katielyn_213)
My favorite month of the year is over, sadly. July in Montreal lived up to expectations as the warmest and most humid month of the year. This July featured lots of sunshine and below-normal precipitation. The rain that did fall was associated with thunderstorms, and thus highly variable across southern Quebec. Officially at Trudeau Airport, 74.2mm of rain fell, below the normal of 89.3mm. I recorded 79mm here on L'Ile Perrot, but almost half of that fell in one thunderstorm. As far as temperatures go, it was warm, with an average daily high of 27.2C (81F), above the long-term average of 26.3C (79F). The average overnight low for the month was 16.8C (63F), also above the normal of 16.1C (61F). The warmest high temperature was 33.7C (93F) at Trudeau, 35C (95F) here on L'Ile Perrot. We managed six days above 30C, with another four days very close, above 29C.

August has started off the same way. This week is expected to be warm, with increasing humidity. High temperatures will be from 28C to 32C (83 to 90F) as the week progresses. A strong cold front will arrive by late Friday, with showers and thunderstorms. At this time, the weekend looks less humid and slightly cooler. Some of you may have noticed a few trees dropping their leaves. This is very early, and likely caused by the very warm and dry July. Heat stress on trees will often manifest itself that way. That being said, we will start to loose daylight rapidly this month, increasing the leaf-shedding process naturally as we head into September.

TORNADO
We had another weekend of severe weather across many portions of North America. Most notable were the two strong tornadoes that occurred between Yorkton and Melville in Saskatchewan on Sunday. Thankfully, no injuries were reported, but widespread damage did occur. One home and farm was completely destroyed. Along the east coast of the United States, the story was flooding. Over 150mm of rain in less than two hours sent torrents of water rushing through Ellicott City, Maryland. The historic town, west of Baltimore, was left in ruins, with two fatalities reported.